


His Butler, Sexual Experimentation

by thedezgyrl



Series: Falling In The Black [3]
Category: Kuroshitsuji | Black Butler
Genre: Anime, Ciel Phantomive is a Brat, Doujinshi, Fem Ciel Phantomhive, Friendship, Gender or Sex Swap, Genderbending, Love, M/M, Manga, NSFW, Original Character(s), Other, Romance, Yaoi
Language: English
Status: Completed
Published: 2015-02-27
Updated: 2015-02-27
Packaged: 2018-03-15 13:13:07
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 1,399
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/3448442
Author URL: https://archiveofourown.org/users/thedezgyrl/pseuds/thedezgyrl
Summary: <blockquote class="userstuff">
              <p>Ciel is unwittingly the guinea pig in an accidental experiment and switches gender. While Sebastian decides to enjoy this turn of events.</p>
            </blockquote>





	His Butler, Sexual Experimentation

**Author's Note:**

> If you are wondering about Johanna, she is an OC in a long running fanfic I coauthor. Practically, she is a half human/half faustian that is contracted to Ciel as well.
> 
> You can read the fanfic she originated from in my works - Falling In The Black
> 
> It is also a loose continuation of my other one shot - 'His Butler, Broken Wing'. Where in the previous one shot he broke his arm. Hence why his arm is injured in this.

Ciel had been having a rough time since he had broken his arm and also had been more cranky than usual. So much so he began to take it on the servants. In an effort to combat her lord's behavior, Johanna decided to concoct a bath oil to soothe him. In her haste to prepare his bath she didn't notice she had grabbed the wrong vial...

After filling the tub with steaming water and adding the home brewed extract which did smell heavenly. She helped his lordship undress and climb inside the tub.

"What scent did you use? Is this new, I have never smelled it before." The earl commented to his dame.

"It is something I made and thought you might enjoy it. Since.." Johanna began to say, but was interrupted by her charge.

"Being a brat?" Ciel mused finishing. Johanna giving him an uneasy look. "It's alright. I know I haven't been the easiest to deal with as of late. I even gave Sebastian the evening off from me."

Johanna looked at him a bit stunned. This must be why he had asked her to bathe him this evening. But she was glad for it. That way she could see how her homeopathic remedy faired.

When the last of the shampoo was rinsed from his hair. The dame who had been sitting behind him on the floor, began to wash down his neck, and as she reached for his chest..gasped with a start.

"What is it?" The boy asked his voice sounding a tad effeminate. Which only caused the servant more panic.

"Umm nothing. I just think it would be better if I were to bathe you from the side." She said as she moved and sure enough her fears after touching him were proven right. Ciel had breasts and as her eyes trailed down to a clear spot between masses of bubbles. She saw under the crystalline water that his sex had changed as well.

There was a knock at the door and Sebastian's voice greeted them, "May I come in for a moment?"  
At the same time, Johanna shouted 'No!' as Ciel simply answered 'Yes.'  
"Well which is it?" The butler asked amused.

Ciel raised a questioning eyebrow to Johanna and gave her a look as to say 'Well?' The dame's face became crimson and the earl's face turned to the door, "Can it wait, Sebastian?"

"Of course, Master." Then they heard the demon's footsteps signaling him walking away.  
Johanna's face was in her hands as the earl turned his attention back to her.

"What is with you tonight?" He asked of her.

"I turned you into a girl!" She said rather loudly into her hands.

Ciel's gaze lowered down to his body and he let out a startled cry. A splash resounded as he stood up and looked at his lower half. A hand going to his mouth in shock.

"I'm sorry! So sorry!" Johanna said to him.

"What did you do to me Hana?!" Ciel demanded.

"I don't know. I must have grabbed the wrong oil." She said.

"You need to fix this! Immediately-" Ciel began to say to her, but was interrupted by another knock at the door. It was Sebastian once again.

"I hear shouting. I am coming in." The butler said.

"Don't" both Johanna and their little lordship started to yell.

Sebastian stood frozen in the open doorway, eyes wide, eyebrows in the perfect placement to show his surprise.

"Oh my word. One of Hana's experiments gone awry?" The demon asked as a hand went to his mouth to stifle a chuckle.

"Don't you dare laugh at me you fool!" Ciel shouted, uninjured arm to his side, fist clenched, and breasts bouncing. When he saw his servant's eyes glued to their jiggling, he snatched up the towel, and wrapped himself as best as he could with a broken arm. Quickly leaving the bathroom with a trail of water behind him from not properly drying.

"How will you fix this my lady?" Sebastian asked Johanna.

"It will wear off in about a week." She replied quietly.

"A week you say?" The demon asked with a glitter in his eye and then practically shoved her out of the washroom and bedroom. The chamber door slamming behind her back.

When Sebastian returned to his young master-the boy was struggling with dressing himself. Even more so with the new physique.

"Johanna said it will dissipate after a week's time." Sebastian told Ciel.  
"A week?!" The earl squealed exasperatedly.

Sebastian was in his face and a ungloved hand grabbed a breast, cupping it, and thumb rotating around the nipple.

"What on earth are you doing?!" Ciel shouted in disbelief.

"Come. Think of all the fun we can have with this." Sebastian asked with a Cheshire grin.  
And before the boy could protest the man's mouth was on his, the hand still on his breast, and a hand on the small of his back as he tilted him back on the bed.

"Shall I mistress?" The demon teased before popping the other breast in his mouth and Ciel squirmed and whimpered. The butler's hand sliding between his master's legs and rubbing a finger around the rosebud. Which caused Ciel's back to arch and his head to lurch to the side.

"All of these foreign sensations...must be overwhelming." Sebastian murmured between kisses and worked his way down. Where his tongue flicked the pink slit and his lips sucked the swelling clit.

"Ahhhmmmm..." Ciel's back arched more and his knees tried to snap around the demon's head. So Sebastian placed his hands on his inner thighs keeping them there and preventing his access from being hindered.

The demon's tongued licked the stretched hole and his tongue dove inside, his teeth lightly nibbled the inner thighs, and his lips sucked the plumpness of Ciel's clit. The boy wiggled, moaned, whimpered, and nearly cried from pleasure.

"I wonder...if my master will have a lady's mark of virtue?" He asked as Ciel looked down at him over his own heaving chest. And his head lulled when Sebastian placed two fingers inside his vaginal cavity probing. "Ah. There it is."

"Not only did I get the first one. I get to take this one as well." The man chuckled as he depantsed himself and grabbed his swollen cock. Placing it at his liege's new entrance and pressing it to it.

"Stop. It won't fit!" Ciel whimpered.

"Shhh master. Don't you trust me?" Sebastian asked as he continued on and it slid in with a 'plopping' sound. Ciel bit the pillow next to him. "Almost there, young master." One more push and there was a feeling of something giving away deeply inside.

Ciel bit the pillow harder and his eyes were squinched tightly. Sebastian gently moved in and out of him. Careful not to make it too uncomfortable for his little lord. After a few moments he began hearing soft moans from Ciel.

"Does it feel better?" Sebastian asked.

There was no verbal reply just a curt nodding of the head. The boy's face completely flushed and his body was constantly spasming all over. Being overcome with all of the foreign sensations of the new body.

Sebastian began to pound harder and deeper inside the boy and as he did so- Ciel's body reacted by clamping around the demon's cock fiercely and his breath hitched.

"Mmm.I do believe you will be orgasming for the first time in this state." As soon as the words left the servant' lips. Ciel's back arched once more, his head rolled around dazed, jaw clenched, and his hips moved in rhythm with Sebastian's movements inside of him.

A sensation overcame Ciel- His lower half felt heated, he squeezed Sebastian's cock tightly internally, his abdomen and leg muscles contracted as a deep moan tore through his chest and out of his throat. All he felt was a surge of wetness from 'down there' as his vision went dark.

Then he felt Sebastian pull out and the warm, stickiness of the demon's come all over his breasts.  
"W-why didn't you climax inside as per usual?" The boy asked groggily.

"We don't know if this body is impregnable, my young master." Sebastian smiled as he lay next to Ciel nuzzling his neck. "Unless..."

"No." The earl said firmly. "Though this whole experience has been...interesting at best."


End file.
